Hydrogen Sensor with Mass Flow Reduction for Fuel Cell Vehicles
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Solution Overview
Problem
Existing hydrogen sensors for motor vehicles with fuel cell drives, using electrochemical cells or chemically sensitive layers, fail to meet industry requirements for life, measurement range, aging, cross-sensitivity, response time, measurement sensitivity, and price.
Innovation Solution
A hydrogen sensor comprising a support with a first temperature sensor, a heating element, and an evaluation unit, along with a mass flow reduction apparatus, which determines hydrogen concentration based on temperature measurements without chemical reactions, using a microsystem design and a family of hydrogen-concentration/temperature characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electrochemical cells or chemically sensitive layers are used for hydrogen detection, then hydrogen concentration can be measured, but the sensor fails to meet industry requirements for life, measurement range, aging, cross-sensitivity, response time, measurement sensitivity, and price
Solution Approach 1:
The patent replaces electrochemical and chemical sensing mechanisms with a thermal field-based measurement system. A heating element heats the sensor surface, and temperature sensors detect temperature changes caused by hydrogen diffusion, eliminating the need for chemical reactions and providing more reliable, consistent measurements across different operating conditions and aging cycles.
Solution Approach 2:
The patent changes the measurement parameter from chemical interaction (electrochemical potential or chemical adsorption) to thermal parameter (temperature change). By measuring temperature changes on the sensor surface caused by hydrogen diffusion, the system achieves better performance in measurement range, response time, and aging stability while maintaining measurement accuracy.
2Measurement precision
If a heating element is added to heat the gas flow, then temperature-based hydrogen detection becomes possible, but device complexity increases
Solution Approach 1:
The patent merges the heating element and temperature sensors into an integrated sensor unit. The heating element is positioned adjacent to the temperature sensors on the same support structure, creating a compact assembly where the thermal field is generated and measured within a small volume, minimizing the increase in device complexity while enabling accurate hydrogen detection.
Solution Approach 2:
The support structure serves multiple functions: it provides mechanical support for the temperature sensors, positions the heating element, and acts as part of the thermal mass for hydrogen diffusion. This multi-functionality reduces the need for additional components and minimizes overall device complexity.
3Measurement precision
If mass flow reduction apparatus is introduced, then accurate temperature measurement is enabled, but the system requires additional components and control mechanisms
Solution Approach 1:
The mass flow reduction apparatus acts as an intermediary between the main gas stream and the sensor measurement zone. It conditions the gas flow to ensure stable, controlled mass flow rates that enable accurate temperature measurements, filtering out turbulence and flow variations that would interfere with the thermal field and measurement precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a cost-effective, accurate, and safe hydrogen detection method that does not require chemical reactions, improving the safety and reliability of hydrogen sensors in motor vehicles by avoiding explosive concentration limits.
Implementation Method 1
The heating element can heat a gas or gas mixture above the heating element or above the support
Implementation Method 2
the first temperature sensor can detect a first temperature
Implementation Method 3
a mass flow reduction apparatus, such that a gas mass flow which flows over the first temperature sensor and the heating element can be reduced
Data Source
AI summary
A hydrogen sensor includes a support having a first temperature sensor, a heating element and an evaluation unit. The hydrogen sensor furthermore includes a mass flow reduction apparatus by which a gas mass flow over the first temperature sensor and the heating element is reduced. The evaluation unit determines a hydrogen concentration in a gas or gas mixture based on a first temperature detected by the first temperature sensor. A detection method for hydrogen concentration having the hydrogen sensor and a motor vehicle having a fuel cell drive having the hydrogen sensor.